On-site Sewage System (OSS) Program
The Public Health On-site Sewage System (OSS) Program helps to ensure that over 85,000 septic systems including 192 septic systems in Seattle are safe. Septic systems treat wastewater when homes and buildings are not connected to public sewer systems. The OSS Program provides educational, advisory and permitting services for owners of septic systems and certifications for several septic professionals.
RESIDENTS ON SEPTIC
Lists of certified professionals
How to take care of septic systems
Building remodel permits
Check your OSS Application status
Online portal submissions
Applications, permits and fees
RESOURCES FOR REAL
Think Before You Flush
During this time when many are staying at home, it is important to keep a careful eye on actions that may affect your sewer or septic system.
Download flyers to learn more:
Septics 101 — Learn the basics
Current focus areas:
Healthy Beach Project
Public Health continues to work with Vashon-Maury Island residents to document improvements to water quality, find sources of excessive bacteria, and, where possible, eliminate these sources. During the 2020-2022 Project, we are sampling water quality, performing visual surveys, and providing free technical assistance and rebates.
Marine Recovery Area
A Marine Recovery Area (MRA) was established to protect especially sensitive marine waters from pollution from poorly functioning or failing on-site sewage systems (OSS). A 2006 state law (RCW 70.118A) required Puget Sound counties (including King County) to designate MRAs where shellfish growing areas are closed due to bacterial pollution (or if closure is likely), or where bacteria or nitrogen are seriously affecting water quality.
Environmental Health Services
14350 SE Eastgate Way
Bellevue, WA 98007
Phone: 206-477-8050 (answered until 3:00 pm)
- Mon. Wed. Fri: 8:00 am to 3:00 pm
- Tues. and Thurs: 10:30 am to 3:00 pm
Link/share our site at www.kingcounty.gov/oss